<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      function makeClass() {
        return class {
          eat = true;
          say() {
            console.log('hello');
          }
        };
      }
      class Rabit extends makeClass() {}
      const r = new Rabit();
      console.log(r.eat);
      r.say();
    </script>
  </body>
</html>
